"Meaning "by way of the anus." "Per annum," with two n's, means "yearly." The correct answer to the question, "What is the birth rate per anum?" is zero (one hopes). The Internet provides many fine examples of the perils of confusing the two. The investment firm that offers "10% interest per anum" is likely to have about as many takers as the Nigerian screenwriter who describes himself as "capable of writing 6 movies per anum" or the Sri Lankan importer whose classified ad declares, "3600 metric tonnes of garlic wanted per anum." The individual who poses the question "How many people die horse riding per anum?" on the Ask Jeeves website has set himself up for crude, derisive blowback in the Comments block." --